1. Field of the Invention
The invention relates to a method for preparing a composition comprising amorphous iron oxide hydroxide and a desulfurizer, in which the composition is the active ingredient, and a method for regenerating the desulfurizer.
2. Description of the Related Art
Due to its good desulfurization performance, iron oxide hydroxide (FeOOH) desulfurizers have been widely used in the fields of chemistry and chemical engineering. Iron oxide hydroxide has several crystalline states, α-FeOOH, β-FeOOH, γ-FeOOH, and amorphous-FeOOH, among which amorphous-FeOOH yields the best desulfurization performance. However, conventional laboratory methods for producing amorphous iron oxide hydroxide require a nitrogen atmosphere to prevent oxidation. The process is, therefore, complicated and unsuitable for mass production. Furthermore, the resultant amorphous iron oxide hydroxide has a compact and less porous structure, a low sulfur capacity, and a low yield.
Conventional desulfurizers have low sulfur capacities. Although the amorphous iron oxide hydroxide-based desulfurizer has a relatively high sulfur capacity, high purity amorphous iron oxide hydroxide is difficult to obtain. The reaction conditions, such as pH value, temperature, and oxidant, used during preparation yield a desulfurizer that contains less than 40 wt. % amorphous iron oxide hydroxide with more ferroferric oxide and ferric oxide. In addition, conventional desulfurizers, including iron-based desulfurizers, cannot be regenerated (or regeneration is costly) so that large quantities of waste product must be buried. The current state of the technology not only wastes resources but also pollutes the environment.